This invention generally relates to an improved apparatus and method for winding magnetic tape, of the type used in recording and playback machines, from a supply reel to a takeup reel. The winding system of the invention finds particular use in the manufacture of continuous loop magazines such as 8-track tape cartridges, though other applications also exist. Most particularly, this invention represents an improvement in the tape winding system described in Applicant's co-pending application, Ser. No. 511,200 filed on Oct. 2, 1974.
In the tape recording industry, particularly that aspect thereof that produces audio programs for consumer entertainment purposes, three familiar tape formats compete vigorously in the marketplace. These formats include the so-called reel-to-reel format, the cassette, and the 8-track cartridge. The reel-to-reel format utilizes a supply reel, on which a tape containing recorded program material is wound. To hear the program material the tape is conventionally fed past a playback head and collected on a takeup reel. After the program has been completed, the tape is ordinarily rewound onto the supply reel.
The cassette is a miniaturized self-contained reel-to-reel system. Like the reel-to-reel format, the cassette has a supply reel and a takeup reel adapted to wind and rewind tape carrying recorded program material. The reels, however, are ordinarily enclosed within a small plastic magazine, which is inserted into a specially adapted machine to achieve the various operative modes such as playback, record and rewind.
Unlike the conventional reel-to-reel format or the cassette, the continuous loop cartridge utilizes only a single reel for carrying tape on which program material is recorded. The tape is wound about the reel in a continuous loop by extracting one end of the tape from the most interior wind and splicing it to the free, outer end. The continuous reel is then conventionally inserted in a plastic magazine, somewhat larger in size than the cassette. A specially designed cartridge player is adapted to play the recorded material upon insertion of the cartridge.
Though the continuously wound 8-track cartridge has numerous advantages over both the reel-to-reel format and the cassette, particularly the fact that it does not have to be rewound after playback, it also suffers from several drawbacks. Among these drawbacks is the fact that the manufacture of 8-track cartridges requires a relatively large amount of labor per unit and has a relatively high reject ratio. This adds to the cost of the cartridges placed on the market, and as a result, the 8-track cartridge has not realized its maximum competitive potential.
Though manufacturing techniques vary, in general, 8-track cartridges are made by starting with a supply reel of tape having a plurality of identical programs recorded thereon. The tape is placed on a winding apparatus and one end is threaded past a capstan and onto an 8-track platform, sometimes referred to hereinafter as a takeup reel. Motors controlling the capstan, the takeup reel, and sometimes the supply reel are then energized, to pull tape from the supply reel to the takeup reel, until the first program is wound onto the takeup reel. After this has been accomplished, the motors are de-energized and the rotation of the reels is stopped.
At a point on the tape beyond the end of the first program slack, the tape is cut to provide a free outer end which, as explained above, is spliced to the interior end wound on the takeup reel to provide sufficient slack. In order to make this splice, the interior end is pulled out from the center of the tape wound on the takeup reel, and attached to the free outer end by conventional means. The takeup reel, now carrying a continuous wound tape program, is then inserted into an 8-track magazine in a well-known manner.
Prior to Applicant's above-identified co-pending application, many winding systems of the prior art undesirably produced uniformly tight winds on the takeup reel. In such systems the inner end of the tape could generally be pulled up from the center only with substantial difficulty. Moreover, oftentimes the tape crinkled when it was pulled, necessitating severance and disposal of the crinkled portion. In his co-pending application, Applicant disclosed a tape winding system which advantageously eliminated tight center winds on the takeup reel.
The advantages are achieved, inter alia, by simultaneously energizing the motors used to drive the takeup and supply reels, causing tape to wind onto the takeup reel at substantially the same rate as the tape is unwound from the supply reel. The energization of the supply reel drive motor is then reduced, thereby allowing tape to be rapidly pulled from the supply reel onto the takeup reel. After an entire program is wound onto the takeup reel, the supply reel and the takeup reel are stopped, making the tape ready for pullout and splicing. Since, at the initial sequence of the winding operation, the tape is wound onto the takeup reel at the same speed it is unwound from the supply reel, minimal tension is placed on the tape, and therefore relatively loose center winds are achieved. As explained above, such loose winds permit pullout with little likelihood of crinkle, thereby preventing tape loss and other manufacturing problems. For a more detailed explanation of the operation and benefits of this tape winding system, reference should be made to the above-described, co-pending application.
Though such a system represents a substantial advance in the art, it is still subject to certain drawbacks and deficiencies. For example, it requires the operator to independently judge when to reduce the energization of the supply reel drive motor, and when to effect the stoppage of both the takeup reel and the supply reel prior to pullout and splicing. Poor operator judgment in such situations could result in spillage, waste or a generally unacceptable product. Moreover, the operator must generally devote his full attention to the winding operation, thereby preventing him from operating more than one winding system simultaneously. As explained in greater detail hereinafter, the automatic tape winding system of the invention obviates these and other prior art difficulties by providing a fully automated system. This eliminates the need for operator judgment in slowing or stopping either the takeup reel or the supply reel, and also frees the operator to perform other tasks even while tape is being wound.